Psych 207 - Module 8: Visual Imagery

Mnemonics, Method of Loci, Pegword Method

Mnemonics: techniques used to increase one's chances of recalling information from prior learning experiences

Method of Loci: for this method to be successful one needs to use a series of well-known places that are encountered in a structured order

• Pick well-known path/locations.

• Place items to remember along the path in order.

• Recall by “walking” the route in your mind.

• Key: Familiar route + vivid imagery = strong recall.

Pegword Method: A memory technique that uses rhyming word-number pairs (pegwords) as retrieval cues.

1. Learn a set of rhyming pegwords (1–10 as an example):
   1 → bun
   2 → shoe
   3 → tree
   4 → door
   5 → hive …

2. Associate each item to remember with its pegword using a vivid mental image.

   • Example: Item #3 = apple → imagine a tree full of apples.

3. Interactive, bizarre imagery works best → the more unusual, the more memorable.

• Creates a fixed retrieval system → easy to recall items in order or by number.

Dual Code Theory

Paivio

Main Idea:

• Memory is better when information is coded in two ways:

  1. Verbal (words/language)

  2. Visual (images/pictures)

• Visual images boost memory because they allow dual storage in memory:

  • Verbal code → word itself

  • Imaginal code → mental picture of the word

Key Prediction:

• Concrete words (e.g., apple, chair) are remembered better than abstract words (e.g., justice, truth),because concrete words can be coded both visually and verbally.

Analog vs. Propositional Debate in Memory

Analog Representation (Image-Based)

• Mental images are like pictures in the mind.

• We can manipulate them as if the object is in front of us.

• Paivio’s Dual Code Theory supports this view:

  • Concrete items → stored as verbal + visual (analog) codes

  • Explains better memory for concrete words

Propositional Representation (Abstract/Verbal)

• Mental images are not pictures → they are abstract descriptions.

• Visual memory is actually verbal or symbolic under the surface.

• Memory advantage for concrete items might come from forming a richer verbal description, not from a true picture.

Zenon Pylyshyn’s arguments:

• Demand characteristics: People “simulate” scanning or rotation because they think they should.

• Implicit knowledge: Prior knowledge of the world drives performance.

• Mind’s eye ≠ true picture → Experience of imagery does not prove storage is visual.

Manipulating Visual Images - Mental Rotation

Shepard and Metzler (1971) -- Mental Rotation

• Task:

  • Participants saw two 3D block shapes.

  • Decide: Same or different shape? (rotated or mirrored).

• Finding:

  • Response time increased with angle of rotation.

  • Suggests participants mentally rotated the object in their mind.

• Supports:

  • Analog view → Mental images behave like real objects we can manipulate.

Manipulating Visual Images - Image Scanning

Kosslyn (1973) – Image Scanning

• Task:

  • Participants studied a map until memorized.

  • Asked to form a mental image of the map.

  • Given a starting point → Asked questions about locations at varying distances.

• Finding:

  • Longer distances → longer response times.

  • Suggests participants mentally “scanned” the image as if it were real.

• Supports:

  • Analog view → We can navigate and manipulate mental images like real ones

Finke’s (1989) 5 Properties of Visual Images

• Implicit Encoding

  • Can access details of an image without intentionally encoding them.

  • Example: Visualizing your bedroom to count windows without planning to memorize it.

• Perceptual Equivalence

  • Imagery uses similar brain systems as actual perception.

  • Supported by:

    • Shepard & Metzler (1971) → mental rotation

    • Kosslyn (1973) → map scanning

    • Brooks (1968) → interference when both tasks require spatial processing.

• Spatial Equivalence

  • Spatial relations in images match real objects.

  • Evidence: Kosslyn’s map scanning → longer distance = longer response.

• Transformational Equivalence

  • Manipulating mental images works like manipulating real objects.

  • Evidence: Shepard & Metzler → RT increases with rotation angle.

• Structural Equivalence

  • Images maintain structure like physical objects.

  • Complex images take longer to form than simple ones (Kosslyn)

Neurophysiological Evidence for Analog Imagery

• fMRI studies show visual cortex activation during imagery tasks (similar to actual perception).

• Suggests mental images recruit the same neural systems as seeing real objects.

Visual Field Overflow

Farah et al. (1992)

• Task:

  1. Imagine an animal at normal size.

  2. Mentally walk closer until the image fills your visual field.

• Finding:

  • Larger animals “fill” the mental visual field sooner than smaller ones.

  • Mirrors real-life perception when approaching physical objects.

• Supports:

  • Analog view → Mental images behave like real visual experiences.

Kosslyn & Patient M.G.S.

• Background: Patient MGS (had severe epilepsy) had part of the occipital lobe removed → smaller physical visual field.

• Finding:

  • Mental imagery field shrank as well.

• Supports:

  • Imagery and perception share the same neural resources (visual cortex).

Color Imagery

De Vreese (1991)

• Finding:

  • Patients with cortical color blindness cannot generate colors in mental imagery.

• Supports:

  • Visual imagery depends on intact visual brain areas → analog representation.

Unilateral Neglect

Bisiach & Luzzatti (1978)

• Finding:

  • Patients with left spatial neglect ignored the left side not only in real scenes, but also in mental images of familiar places (e.g., their town square).

• Supports:

  • Imagery uses the same spatial attention systems as real perception.